def targets = 'clean default'
if (args) {
    targets = args.join(' ')
}

new File('.').traverse([type: groovy.io.FileType.DIRECTORIES, maxDepth:2]) { project -> 
    def script = new File(project,'build.xml')            
    if (script.exists() ) {
        
        def out = new StringBuffer()
        def err = new StringBuffer()
        println "-" * 50
        println "processing: $script ($targets)" 
        def proc =  "cmd /C ant $targets".execute(null,project)
        proc.consumeProcessOutput(out,out)
        proc.waitForOrKill(480 * 1000)
        new File(project,"build.log").text = out.toString()               
        println out 
    }
}